Steel retainer



G. G. TUTTLE STEEL RETAINER- July 15, 1930.

Filed Dec. 21, 1927 2 Sheets-Sheet l INVENTOR. G1 492 BY H15 ATTO '1 EVy 15, 1930- G. G. TUTTLE 1,770,680

STEEL RETAINER Filed Dec. 21, 1927 2 Sheets-Sheet 2 IN VEN TOR.

i770 0117.7 file H15 ATTOR EY' l atentecl July 15, 1930 {U ITED STATESPATENT caries.

v GROVERG. TU'ITLE, OF PHILLIISBURG, NEW JERSEY, ASSIGNOR TINGEESOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEWJERSEY s'rn'nn RETAINER Application filed December 21', 1927. 'SerialNo. 241,556.

' cates relatively to the drill steel.

The objects ofth'e invention are to maintain the drill steel in thefronthead, to render the retainer flexible, to prevent breakage of y theretainer and to insure against its accidental oscillation from theretaining position. r

Other objects will be in part obvious and in p art' pointed outhereinafter.

' Inthe drawings illustrating the invention, Figure 1' is an elevationof the front end-of V a 'rock'drill having the retainer applied there-Figure2 is view similar to Figure 1 showing another View of theretainer, 7

Figure 3 is an end view offthe retainer,';and Q Figures 4, 5 and Gareside elevations of modified forms of the invention. A i V Referring moreparticularly to the drawings, the invention is shown applied to a rockdrill, only the front head A and a portion of the cylinder B of whichare shown. These "parts, together with others (not'shown) comprise thecasing of the drill and are held in operative position by spring pressedside bolts G disposed on opposite sides of the drill. The front head Amay be of a well known type which actsas a guide for a drill steel Dinserted in the front end of the front head.

Only the body portion of the drill steel D is shown. It is, however, tobe understood that the drill steel may be of a type provided with ashank adapted to extend into the path of a hammer piston (not shown)reciprocable in the cyli'nder B.

At the rearward end of the body portion of the'drill steel D is formed acollar F which,

vduring the normal operation of the drill,

abuts the front end of the front head for limiting the distance whichthe drill steel may extend into said front head.

' jOn opposite sidesof the front head are formed trunnions G ofcylindrical shape. The trunnions G areoff-set with respect to thelongitudinal axis of the front head'and may belocated in anyconvenientposition relativelyto the extremities of the front head.

In accordance with the present invention, means are provided forpreventing ejection of the drill steel D from the front head upon theimpact of the hammer piston against the drill steel and moreparticularly whenever there is'i'nsuficient resistance to the cuttingbit of the drillsteel to maintain the drill steel in its rearwardmostlimiting position with respect to the drill. These meanscomprise a steelretainer llwhich consists of a single piece of wire bent intermediateits ends to form a yoke J. The yoke J is of U-shape and partly encirclesthe drill steel D forwardly of the collar F at a distance sufficientlyre moved therefrom to permit limited reciprocation of the collar Ftogether with the drill steel D without impacting against said yoke. Theyoke J has integral side arms generally designated by K which extend ina rearwardly direction on opposite sides of the front head A; The sidearms K terminate at their rearward ends in spiral springs L forcushioning the retainer against the effects of the blows of the drillsteel on the yoke J. The springs L may consist of anysuitable number ofcoils depending upon the type of front head and the position in which itis desired to mount the retainer thereon. The inner coils O of thesprings L are of such form asito snugly receive the trunnions'G whereonthe retainer H is pivotally supported.

As is well known, retainers of the type to which the present inventionpertains are sub jected to severe usage and efforts are constantly beingmade to render them flexible without sacrificing the essential propertyof strength. In order to incorporate this desirable quality offlexibility in the retainer, the

"side arms K are provided with coils P at their juncture with the yokeJ. The side arms K have rearwardly extending straight portions Q whichare engaged by slots R in'the sides of the front head A. for the purposeof preventing unintentional displacement of the retainer H. The rearwardends of the straight portionsQ; of the s1de arms are developed intocoils S located intermediate the coil springs L and the straightportions Q. The coils S are reversely wound with respect to the coil srin s L and the coils S and springs L of eac si e arm are preferablyaligned parallel to the axis of the drill steel D.

collar F. With the retainer in this position,

the rock drill and the drill steel D may be removed from the vicinity ofthe drill hole as a unit since the oke J will engage the collar F andenable t 1e rock drill to be used as an plement for pulling the drillsteel D out of the drill hole. 7

Whenever it is desiredto remove the drill steel. Dead substitute anothertherefor, the

retaiuerH we be oscillated about the trunnimm G a su cient distance toremove the yoke Jout of the. ath of the collar F. After another steelhas een inserted intothe front held, the retainer may again be rocked toits retaining position wherein it will be held by them-coves R. r y

a Imthe modification illustrated in Figure 4,

i the retainer T, like that shown in the preferred modifications,consists of a single piece ofmire bent intermediate its ends to form ayoke U to serve as an abutment for the collar of. the drill steel.Theretainer has upwardly extendin side armsV. which are connected to theyo e U by curved rtions W. At the rearward ends of the si e arms V areformed the spiral springs L for absorbing the blows of the drillmolagajnst the yokeU. Straight portions X extend rearwardly from thecurved portions W and develop into coils S adjacent the rings L andreversely wound with respect thereto to cooperate withthe springs L forcushionin the yoke against the effects of the blows of t e drill steeland to eliminate angulaistresses in the side arms. The modificationshown in Figure 5 is ada tad more particularly for use on rock dri onwhich the pivotal points or trunnions G are so located as to precludethe use of cushionin --means at this extremity of the retainer. T e sidearms of the retainer are rovided at their rearward extremities with oopsor coils Y for pivotally engaging the trim-niche. The loops Y may beextended to form coils Z intermediate the ends of the retainer and saidcoils Z are developed into comprises a yoke U connected to the side armsd by means of coils e. The straight portions f of the side arms d are solocated with respectto the yoke U as to enable them to lie in thegrooves R of the front head when the retainer is in its retainingposition. At the rearward ends of the side arms (1 are formed the spiralsprings L which cooperate with the coils e for absorbing the blows ofthe drill steel against the yoke U. i

The operation of the modified forms of retainers shown in Figures 4, 5and 6 is substantially like that previously described in connection withthe retainer shown in Fi ures'l t6 3 inclusive. As may be readily 0%-served, the retainers shown in the modifications differ with respect toeach other in the matter of flexibility. These structural differencesrender them particularly applicable for various types of drills and forcertain usages. These retainers,- however, as that in the preferredmodification are sufficiently yieldable to enable them to fullywithstand the severe blows to which they are subjected.

A few of the desirable features of the invention are that thoseportions, as for instance the straight portions of the side arms, whichare in engagement with the front head for locking the retainer inretaining position lie 111 planes parallel with the plane of movement ofthe retainer upon the impact of the drill steel thereagainst. Lateraldisplacement of the straight portions during the movement of theretaineris'prevented by the secondary coils placed between the straightportions and the coils at the ends of side arms. As a result of thisconstruction the retainers are not subjected to the severe angularstresses which are largely responsible for the excessive breakage ofretainers of this type.

Another advantageous feature of the present invention is the protectionafforded the retainer b forming the coils adjacent the yoke. Thisconstruction has been found to further eliminate the chances of breakagesince a positive s ring effect is provided for the retainer at t atpoint at which the retainer is called upon to withstand the most severestrains.

I claim 1. In a steel retaining device for rock drills, the combinationwith a front head having trunnions, a drill steel guided by the fronthead, a collar on the drill steel, and a retainer comprising a yoke toact as an abutment for the collar and side arms on the yoke terminatingin coils for engaging the trunnions, of secondary coils adjacent thefirst said coils and being reversely wound with respect thereto, andstraight portions on the side arms forwardly of the return bent portionsof said secondary coils and adapted to engage the front head to preventaccidental oscillation of the yoke from the retaining position.

2. In a steel retaining device for rock drills,

the combination with a front head having cylindrical trunnions, a drillsteel guided by the front head, a collar on the drill steel, and

a retainer comprising a yoke to act as an abutment for the collar andside arms havlng integral spiral sprlngs at their rearward ends,

the innermost coils of said springs being adapted to pivotally engagethe trunnions, of secondary coils adjacent said springs and beingreversely wound with respect thereto, said springs and said secondarycoils on each side arm being aligned parallel to the axis of the drillsteel, and straight portions on the side arms forwardly of the returnbent por-' tions of said secondary coils and adapted to engage the fronthead to prevent accidental oscillation of the yoke from the retainingposition. v v

In testimony whereof have signed this specification.

GROVER G. TUTTLE;

